Adjustable surfacer.



Fe E. RUDOLPH.

ADJUSTABLE SURFACER.

APPLICATION FILED SEPT. I. 1915.

FREDERICK E. RUDOLPH, 0F CHICAGO, ILLINOIS.k

ADJUSTABLE SURFACER.

Speccation of Letters Patent.

Patented Dec. 28, 191,5.

Application filed September 7, 1915. Serial No. 49,321.

.To all whom t may concern Beit known thatA I, FREDERICK E. RU- DOLPH, a citizen of the United States, residingat Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements 'in Adjustable Surfa'cers, of Which the following is a speciication;

Myinvention relates to adjustable means for surfacing objects having generally rounded contours. f

One of the lobjects'of my invention is to provide means for holding a sheet of abrading material, `such as emery cloth, sand paper or the like, which is quickly adjustable to present a surface that will conform to the surface to be dressed or tri-led up by the device, to thereby provide a backing for the abrading sheet to be carried thereby.

A special obj ect of my invention is to pro-` vide a device for truingl up and polishing the cylindrical Aworking surface vof a rotating commutator, of a dynamo electric machine, capable of adjustment to provide'a concaved surface, corresponding to and substantially concentric with the convex surface of said con1mutator,.and means for holding a sheet of abrading material in position 4overlying the backing up surface of the device.

Other and more specific objects of-my in-l vention will become readily apparent to persons skilledin the art, from a consideration of the following description when taken in conjunction with the drawings, wherein:-w

Figure 1 is an elevation of a broken-:mayI

portion of the comrnuator showing the surfacing block applied thereto. Fig. 2 is an end View ofthe block. Fig. 3 is asection taken o-n line 3-3 of Fig. 2. Fig. 4 is a section taken on line et--L of Fig. 3. 5 is an elevation ofone form of the lalninzeI or sheets of insulating material of which the block is largely composed. Fig. 6 Ashows a modied form of the lalninae and one form of the insulated guiding portions for the laminac. Fig. 7 is -a section taken on line 7 of Fig. 3.

In all the views the same reference characters are employed to indicate similar Darts.

A The block 10, is shown in Fig. 1, as ap` plied to the comm'utator 11. Thel block is composed of a series of, perforated laminae or sheets 12, vof insulating material, each sheet having-one or more perforations, such as 13, 11, and 15, or having a single perforation 16 :as shown in the modification. In Fig. there are three guiding blocks 17, 18 and 19, for the perforations 13,1% and 15,

respectively. The perforations, in every instance, are vertically. of larger dimensions shown in Fig. 4, and is adapted for blocks of smaller dimensions; The sheets 12, composing the laminated structure of the blocks, may well be made of vulcanized fiber each about 1/64; of an'inch thick, butI prefer to have a thigker sheet of fiber at the terminal ends of the assembled inner sheets, such as shown at 22 and 23. Metal terminal plates 24, such as shown in Fig. 2, one on each side of the block, are perforated for the clamp ing screws 25-25.

The guiding blocks 17, 18 and 19, shown in Figs. 3 and 4, are rectangular in cross section. The longer portion 17 is transverselv perforated to receive a metalscrew* threaded plug 26, to receive 'the longer clamping screws 25; A similar plug 26 is transversely positioned lin the block 21, shown in Fig. 6, and perforated and threaded to receive similarl screws for ,the same purpose. The blocks, suchas 17, 18, 19. 20

and 21, respectivelv, have broken joints, as

shown, so-that the lamina, supported on the blocks, will not pass in between the confronting surfaces of the adjacent ends.

0n each'of the plates 24 is mounted a spring pressed clip 27. having their front ends normally held away from the plate 24. by means of springs 2S. Said clips are pivotallv mounted upon pins 29 in brackets secured to the respective plates. A screw 30. having an oblong head 31 passes through a similar perforation 32, in ,the insulating plate 22. made oblong to prevent the screw from turning and then passes through the clip 27. A knurled threaded nut 31 passes over the screw 30, and serves as means for holdingthe front end of the clip 27 in more positive relation with the plate 24 to retain therebetween a sheet or fabric of abrading material 33, such as emery cloth, sand paper or the like.

Io adjust and apply the'device to a commutator, for the purpose of truing up the working surface of the commutator, the screws are loosened and t e front end surface of the block is first ap lied to the colnmutator and each laminae is pressed toward the commutator from the rearend until the general contour contacting end of the block is substantially the same circumferential configuration as the face of the commutator, at which time the clamping screws 25 are tightened to hold the laminated structure in adjusted position. A strip of sand paper 33 is then put under one clip 27, as shown in, Figs. 1 and 3, and the other end ofthe strip is placed under the clip on the opposite side of the block. The thumb screws 31 are then turned to tighten the clips, when the device is ready for use.

By pressing the abrading sheet carried by the block 10 into firm contact with the commutator the surface of the commutator will thereby be perfectly trued by the abrading effect of the sand paper, emery cloth or the like. Should the commutator be of larger diameter, as 'shown by dotted lines 34, the block can be made to conform to the larger circumferential surface of the commutator in the same manner as heretofore described. And thus the block may be used upon commutators of varying and various diameters.

A block may be quickly and easily adjusted for comlnutators of various diameters, within a reasonable limit, and will' thereafter present a substantially uniform-continuous surface, concentric with the surface of the commutator tol be trued, and serving as a* backing for the abrading paper orcloth used for the purpose, whereby the entire surface of the paper or cloth may be brought into contact with the commutator.l i

It will be observed that all of the metallic parts of the block when in use are perfectly insulated from the commutato" "md for this reason the block may be used for truing purposes while the armature is energized, if so desired, Without'danger of short circuiting any parts of the armature by accidental con- Copies of this patent maybe obtained for tact of the metal parts with the-commutator thereof.`

While I have herein shown .and described a preferred embodiment of my invention,

of insulating material; Va guide for said.

sheets within said perforations, to permit relative'longitudinal movement and toprevent lateral movement thereof said guide' comprising two longitudinally alining parts; means comprising alining screws taking through opposite ends of the guide. and screw, l'threaded into only one part thereof to clamp and hold the sheets by frictional engagement; a clip on each side of the device near one end, to engage and hold a' sheet of abrading fabric over said end, of

the device and means to tighten the clip over said fabric.

2. A device of the. character described comprising a series of perforated, parallel longitudinally movable sheets of insulating material; metal terminal plates; guides within said perforations, ,comprising two parts relatively movable, one -saidfpart of each guide secured to one terminal plate.; a screw passing through the opposlte terminal plate and the other guiding part of each guide and intothecompanion part thereof,

whereby to clamp the parts together and a fabric engaging clipl on each said terminal plate.

In testimony whereof I hereunto set my hand in the presence of two subscribing witnesses.

FREDERICK E. RUDOLPH.,

In the presence ofl l MARY F. ALLEN, FOR BAIN.

five cents each, by addressing the Commissioner of Patents. Washington, D'. C. 

